There may be 1-2cm deviation due to the listed size. We also carry other angles and muffler bands. Please feel free to contact us. If you would like a set of 2, 3, or 4, we also sell them separately. We do not support installation. Processing may be required, so please be sure to ask a professional who can install it. Instructions not included. Please be sure to check and understand before making your purchase. (You will be aware of everything at the time of purchase. )